Fabric softener compositions



United States Patent 3,256,180 FABRIC SOFTENER COMPOSITIONS Walter F.Weiss, Wheaten, Ili., assignor to Arthur D.

Little, Inc., Cambridge, Mass., a corporation of Massachusetts NoDrawing. Filed July 23, 1963, Ser. No. 296,894 6 Claims. (Cl. 2528.8)

This application is a continuation-inpart of my copending application,Serial No. 216,763, filed Aug. 14,

1962, now abandoned.

This invention relates to compositions useful for imparting softness tofabrics and man improved process for producing a fabric softenercomposition in a form most convenient for distribution and use.

At the present time, compositions useful for treating fabrics to improvethe softness and feel characteristics thereof are known in the art.Normally, these softener compositions designated fabric softeners whichare employed to treat fabrics during laundering are liquids whichcontain as the principal active component a quarternary ammoniumcompound, that is a substituted ammonium salt in which all four of thehydrogens of the ammonium radical are substituted by organic radicals,or other cationic nitrogen-containing compounds such as amines. Theliquid nature of these fabric softeners detracts considerably from theircommercial acceptance. While the physical form of a fabric softenercomposition does not affect its fabric softening properties, conveniencein packaging, distribution and use makes a solid form extremelydesirable. Accordingly, a major object of this invention is to provide afabric softener composition of excellent softening characteristics in asolid form.

When used in domestic laundering, the fabric softeners are added to therinse Water during the rinse cycle which is generally from about 3 to 5minutes duration. Consequently, the fabric softener must be capable ofrapid dispersion in the rinse water so as to produce an effectiveconcentration of the product therein for fabric softening in therelatively short period of the rinse cycle. Liquid fabric softenerspresent no serious problems in this connection, however, the same cannotbe said for fabric softeners in solid form. The physical form of thefabric softener has been found to be of considerable importance inachieving rapid dispersion in the rinse water during the rinse cycle andin particular it has been found that the solid fabric softener should bein the form of relatively thin flakes having a thickness notsubstantially in excess of about 0.025 inch and preferably about 0.005to 0.015 inch. It is therefore a further object of this invention toprovide a fabric softener composition which can readily be produced inthe form of relatively thin flakes capable of rapid dispersion in water.The fabric softener composition can also be produced in granular form.

The significant, readily apparent improvement in the softness of fabricsresulting from the use of fabric softeners has resulted in the creationof a large and expand ing consumer market for these products. Thiseconomic fact dictates that the fabric softener compositions beefficiently produced in large amounts in minimum process ing time. It istherefore another object of this invention to provide a process forproducing a fabric softener composition in solid form which process iscapable of producing large quantities of the softener compositionquickly and with the use of readily available production equipment.

The principal active component of the present fabric softenercomposition is a cation-active organic compound having fabric softeningproperties. These cation-active organic compounds, which can be used asactive fabric softeners, are known to the art and generally comprisecationic nitrogen-containing compounds such as quaternary ammoniumcompounds, and amines containing one or two straight-chain organicradicals of at least 8 carbon atoms and preferably from 12 to 22 carbonatoms. Representative of preferred cationic compounds are quatern aryammonium compounds having one or two straightchain organic radicalscontaining from 12 to 22 carbons atoms; primary, secondary and tertiaryamine compounds having at least one straight-chain organic radicalcontaining from 12 to 22 carbon atoms; 1,3-propylene diamine compoundshaving a C to C straight-chain organic radical and like compounds.Specific preferred fabric softening compositions include such compoundsas di-(hydrogenated tallow) dimethylammonium chloride, di-(hydrogenatedtallow) dimethylammonium methyl sulfate, primary tallow amine, primaryhydrogenated tallow amine, tallow 1,3-propylene diamine, oleyl1,3-propylene diamine and coco 1,3-propylene diamine, di-(soya)dimethylammonium chloride, and d-(coco) dimethylammonium chloride.

The cationic nitrogen-containing component constitutes from about 4 toabout 40 percent, preferably from about 18 to 25 percent by weight ofthe softener composition of the invention. Urea which is reacted withthe cationic nitrogen-containing compound to form an adduct constitutesthe major component of the softener composition and is employed inamounts ranging from about 50 to percent by Weight. The urea should beemployed in an amount at least equal to that stoichiometrically requiredfor reaction with the cationic nitrogen-containing known to the artwhich are suitable for use in the present fabric softener compositionsuch as, for example, Triton X- (a condensate of isooctyl phenol withabout 8 moles of ethylene oxide), Ethomeens (oxyethylated secondaryamines), Hyonics (e.g. fatty alkylolamides) and the like. The aboverepresentative wetting agents can be employed in the fabric softenercompositions of the invention in amounts ranging from about 1 to 20%.Moreover, if desired, any suitable perfume or dye can be employed in thesoftener composition to improve the esthetic attractiveness of thesoftener product to the ultimate consumer. Such dyes and perfumes areemployed in relatively small amounts, generally less than about 0.25percent by weight of the composition.

A typical finished fabric softener composition prepared in accordancewith the invention is as follows, the parts being by weight:

Dye 0.005

The preparation of the fabric softener compositions is carried out inaccordance with the invention "by blending the urea, cationicnitrogen-containing compound and other components of the composition inthe presence of a specified amount of water. I have found surprisinglythat in order to achieve a solid granular product which can be readilygranulated or flaked to the desired size, it is necessary to add waterto the reaction mixture in a relatively narrow and critical range. Moreparticularly, it is necessary to employ water in the reaction mixture inan amount from about 2 to about 15 percent and preferably from 3 to 5percent of the softener composition. Employing water in the specifiedproportions and effecting reaction of the urea and cationicnitrogen-containing compound in'the presence of the water constituteimportant features of the present invention. If less or substantiallymore than the stated amounts of water are employed in the preparation ofthe fabric softener composition, the products do not solidifysatisfactorily and do not granulate or flake readily.

In one embodiment of the invention, urea is charged to a suitable mixingvessel and the cationic nitrogen-containing compound mixed therewith,preferably in liquefied form. The reaction is effected at substantiallyambient temperatures. The cationic nitrogen-containing compound can besupplied to the reaction site in the form in which it is availablecommercially such as, for example, dissolved in low molecular Weightalcohols. The requisite amount of water specified above, namely fromabout 2 to about 15 percent and preferably from 3 to 5 percent by weightis added to the mixture and the mixture agitated for a short period, forexample, 58 minutes,

until a homogeneous granular product is produced. The requisite watercan be added to the reaction mixture before or after addition of thecationic-nitrogen-containing compound. Any water inherently present inthe ingredients of the composition must be taken into account. Thewetting agents in liquid form and dyes and perfumes, if any, areincorporated into the reaction mixture prior to solidification of thegranular product. The granular product obtained from the reaction isthen milled on rolling mills or the like to produce relatively smallgranules or thin flakes. The resulting particles are then screened to adesired size and the finished fabric softener composition packaged fordistribution. The finished fabric softener product generally containsless than about 1% water.

The following specific examples will further illustrate the invention,the parts indicated being by weight unless otherwise indicated.

EXAMPLE I Three hundred grams of urea are charged into a mixing bowlsuch as a S-quart Hobart mixer. Ninety grams of a quaternary ammoniumcompound, di-(hydrogenated tallow) dimethylammonium chloride and 7.5grams of a second cationic surface active agent, liquefied by warming,are added to the urea charge and blended for 30 to 45 seconds at mediummixing speed. A solution of 3.7 grams of an organic nonioni-c surfaceactive agent in 8 grams of water, containing a perfume and solublecoloring dye is added to the blend of urea, quaternary ammonium compoundand surfactant while mixing is continued.

The total amount of water employed corresponds to about 3% by weight ofthe mixture. Within 30 seconds after the addition of water a stiff doughforms. Within two minutes after the addition of water the doughy massbegins to granulate. Within 5 to 6 minutes after the ad dition of watergranulation is completed.

A slightly moist non-greasy or non-waxy granulation is produced in lessthan eight minutes which can be passed through a flaking mill to producea thin brittle flake.

These flakes are capable of rapid solution and dispersion in anautomatic washing machine. Cationic fabn'c softener is liberated anddispersed by destruction of 4 the flake and made available fordeposition on the fabric being treated. The fabric softener prepared asindicated was evaluated as follows:

Subjective examination of treated fabric Fabrics treated:

New gauze diapers scoured by 2 normal washings before treating withsolid fabric softener. New turkish towels scoured by 1 normal washingbefore treating with solid fabric softener.

[Gauze diapers examined by a 5 member panel] Treatment:

Four grams of solid softener, rinse cycle treatment of a six pound load.

Three out of five panel members selected the treated diapers as softerthan a control handled in an identical manner except for addition ofsolid softener in the rinse cycle.

Treatment:

Eight grams of solid softener, rinse cycle treatment of a six poundload.

Four out of five panel members selected the treated diapers as softerthan a control handled in an identical manner except for the addition ofsolid softener in the rinse cycle.

Treatment:

Fifteen grams of solid softener, rinse cycle treatment of a six poundload.

Five out of five panel members selected the treated diapers as softerthan a control handled in an identical manner except for the addition ofsolid softener in the rinse cycle.

[Turkish towels examined by a 5 member panel] Treatment:

Ten grams of solid softener, rinse cycle treatment of a six pound load.

Five out of five panel members selected the treated.

towels as obviously softer than a control handled in an identical mannerexcept for the addition of solid softener in the rinse cycle.

EXAMPLE A H Three-hundred grams of urea are charged into a mixingvessel. Ninety grams of a quaternary ammonium compound purchased fromEmery Industries and designated Emery 3484-D and 7.5 grams of a secondcationic surface active agent, liquefied by warming, are added to theurea charge and blended for /2 minute. A water solution containing eightgrams of water, 3.7 grams of an organic nonionic surface active agent,perfume and coloring are added to the blend with continuing mixing. Thewater employed corresponds to about 3% of the total mixture. A greasymobile dough is formed which begins to granulate in about 6 minutes andis completed in about 11 minutes.

The granules formed are soft and somewhat self adherent but flakereadily in one pass through cold flaking rolls. The flakes are soft andwaxy initially but become somewhat brittle after several hours of aging.

EXAMPLE III Three hundred grams of urea are charged into mixing vessel.Ninety grams of a quaternary ammonium compound, di-(hydrogenated tallow)dimethyl ammonium chloride and 7.5 grams of a second cationic surfaceactive agent, liquefied by warming, are added to the urea charge andblended for /2 minute. A mixture of 2 grams total of water, 3.7 grams ofan organic nonionic surface active agent, perfume and dye are added tothe blend. The total amount of water employed corresponds to about 1.5%by weight of the mixture. A mobile greasy slurry is produced whichbegins to break up after 3 to 4 minutes into a soft irregulargranulation as the quaternary ammonium compound cools below itsliquefaction temperature. The product is unsatisfactory in that thegranulation is greasy and easily compacted and diflicult to handle.

The soft greasy granulation must be flaked with cold rolls. The flakeproduced is soft, pliable and distinctly greasy. The flake becamebrittle :and non-greasy after about 24 hours of aging.

EXAMPLE IV Three hundred grams of urea are charged into a mixing bowlsuch as a S-quart Hobart mixer. Ninety grams of a quaternary ammoniumcompound, di-(hydrogenated tallow) dimethylammoniumchloride and 7.5grams of a second cationic surfactant liquefied by warming, are added tothe urea charge and blended for about /2 minute at medium speed. Asolution of 3.7 grams of an organic nonionic surface active agent in 60grams of water containing a perfume and a soluble coloring dye is addedto the blend of urea, quaternary ammonium compound and wetting agentwhile mixing is continued. The amount of water employed, together withthe Water inherently present in the ingredients corresponds to about 16%by weight of the mixture. An extremely heavy dough results almostimmediately. Granulation of a mixture containing this much water iseffected only with difficulty and if granulation does occur it generallyreverts to a stiff dough with continued mixing. The product can bemilled into a flake product only with difficulty and requires manypasses between mill rolls accompanied by drying of the product beforeflaking occurs.

EXAMPLE V The data in the following table shows the significance of theamount of Water added during the mixing and reaction of the cationicnitrogen-containing compound and urea. The products were extracted withchloroform with the chloroform-soluble fraction indicating theproportion of cationic nitrogen-containing compounds that have notcomplexed with urea.

The di-(hydrogenated tallow) dimethylammonium chloride as soldcommercially contains 75% active ingredient with the other 25% beingabout 6% water and 19% isopropyl alcohol. Therefore, in addition to theadded water shown in the above table, the reaction mixture alsocontained 1.3% Water and 4.2% alcohol introduced with the quaternary.

EXAMPLE VI chloroform-soluble values were determined on a variety ofother products and are summarized in Table II. The amounts of water andalcohol shown are the total amounts present including whatever may beinherently introduced with the active ingredients. All of the productswere formulated to contain approximately 22% by weight of the cationicnitrogen-containing compound.

TABLE II In Reaction Mixture Percent Active Ingredient ChloroformPercent Percent Solubles Water Isopropyl Alcohol Primary Amines:

Hydrogenated-tallow amine 6 2. 2 Coco amine 6 4 3. 5 Arachidyl-behenylamine 2 8 5. 0 Secondary Amines:

Di-soy amine 2 10. 4 Di- (hydrogenated tallow) amine 2 6 17. 2Di-(arachidyl-behenyl) amine 2 16. 7 Tertiary Amines: Di-methylhydrogenated-tallow amine 4 5 4. 8 Quaternary Ammonium Oompounds:

Tallow trimethyl ammonium chloride i 3 4 0. 7 Di-(hydrogenated-tallowdimethyl ammonium sulfate 3 4 5. 0 Dicoco dimethyl ammonium chloride 5 42.0 Di-soy dimethyl ammonium chloride 3 4 3. 8 Diamines:

Coco 1,3-propylene diamine 2 5. 4 Tallow 1,3-propylene diamine. 5 6. 3Oleyl1,3-propylene diamine 10 5 7. 3 Arachidyl-behenyl 1,3-propylenediamine 12 0. 7

The importance of employing water in the specified proportions duringthe preparation of the fabric softener composition is apparent from theabove as is the speed with which the solid fabric softener of theinvention can be prepared.

The fabric softener compositions of the invention lend themselves topackaging and packages may be made of sealed containers containing anydesired amounts of such compositions which, being in dry form, may bereadily distributed or shipped without difliculty. During such shipmentthey do not pack or compressor cake and are directly available withoutfurther preparation for use in treating fabrics to improve the softnessand feel characteristics thereof. Moreover, the fabric softenercompositions can be prepared at ambient temperatures which is anadditional advantage.

Those modifications and equivalents which fall within the spirit of theinvention and the scope of the appended claims are to be considered partof the invention.

I claim:

1. A process of preparing a stable solid water-dispersible compositionuseful for treating fabrics to improve the softness characteristicsthereof which comprises reacting at substantially ambient temperaturesin the presence of water a major amount of urea ranging from about 50 topercent by weight of the composition and a cationic nitrogen-containingcompound containing one to two straight-chain organic radicalscontaining from 8 to 22 carbon atoms and having fabric softening properties, the amount of water present in the reaction mixture correspondingto from about 2 to about 15 percent by weight of the composition.

2. A process of preparing a stable solid water-dispersible compositionuseful for treating fabrics to improve the softness characteristicsthereof which comprises reacting at substantially ambient temperaturesin the presence of water a major amount of urea ranging from 50 to 90percent by weight of the composition with a cationic nitrogen-containingcompound containing one to two straight-chain organic radicalscontaining from 12 to 22 carbon atoms and having fabric softeningproperties, the amount of water present in the reaction mixturecorresponding to from about 3 to about 5 percent by weight of thecomposition.

3. A process of preparing a stable solid water-dispersible compositionuseful for treating fabrics to improve the softness characteristicsthereof which comprises re- 7 acting at substantially ambienttemperatures in the presence of water a major amount of urea rangingfrom about 50 to 90 percent based on the weight of the final compositionand about 4 to 40 percent based on the weight of the final compositionof a cationic nitrogen-containing compound containing one to twostraight-chain organic radicals containing from 8 to 22 carbon atoms andhaving fabric softening properties, the amount of water present in thereaction mixture corresponding to from about 2 to about 15 percent byweight of the reaction mixture, agitating said reaction mixture for aperiod of time suffi: cient to produce a solid reaction product,removing said solid reaction product and flaking the solid reactionproduct to produce flakes.

4. A process of preparing a stable solid water-dispersible compositionuseful for treating fabrics to improve the softness characteristicsthereof which comprises reacting at substantially ambient temperaturesin the presence of water a major amount of urea ranging from about 50 to90 percent based on the weight of the final composition, about 4 to 40percent of di-(hydrogenated tallow) dimethylamrnonium chloride, theamount of water present in the reaction mixture corresponding to fromabout 2 to about 15 percent by weight of the reaction mixture,

agitating the said reaction mixture for a period of time sufficient toproduce a solid reaction product, and flaking the solid reaction productto produce a finished flaked product ready for use.

5. A process of preparing a stable solid water-dispersible compositionuseful for treating fabrics to improve the softness characteristicsthereof which comprises reacting at substantially ambient temperaturesin the presence of water a major amount of urea ranging from about topercent based on the weight of the final composition with hydrogenatedtallow amine, the amount of water present in the reaction mixturecorresponding to from about 2 to about 15 percent by weight of thecomposition;

6. The product resulting from the process of claim 1.

References Cited by the Examiner UNITED STATES PATENTS 2,584,056 1/1952Soule et al. 252152 XR 2,584,057 1/1952 Soule et al 252-152 XR 2,676,9554/ 1954 Weitkamp 26O96.5

JULIUS GREENWALD, Primary Examiner.

J. T. FEDIGAN, Assistant Examiner.

1. A PROCESS OF PREPARING A STABLE SOLID WATER-DISPERSIBLE COMPOSITIONUSEFUL FOR TREATING FABRICS TO IMPROVE THE SOFTNESS CHARACTERISTICSTHEREOF WHICH COMPRISES REACTING AT SUBSTANTIALLY AMBIENT TEMPERATURESIN THE PRESENCE OF WATER A MAJOR AMOUNT OF UREA RANGING FROM ABOUT 50 TO90 PERCENT BY WEIGHT OF THE COMPOSITION AND A CATONICNITROGEN-CONTAINING COMPOUND CONTAINING ONE TO TWO STRAIGHT-CHAINORGANIC RADICALS CONTAINING FROM 8 TO 22 CARBON ATOMS AND HAVING FABRICSOFTENING PROPERTIES, THE AMOUNT OF WATER PRESENT IN THE REACTIONMIXTURE CORRESPONDING TGO FROM ABOUT 2 TO ABOUT 15 PERCENT BY WEIGHT OFTHE COMPOSITION.